journalctl: how to prevent text from truncating in terminal

Question

How can I keep long strings from truncating in terminal? For example if I run

journalctl -xn

There's a lot of text that I cannot read. I am open to using other programs/tools.

Use journalctl -x, -n default to 10 lines in log only. – cuonglm Sep 12 '15 at 02:24 — cuonglm, Sep 12 '15 at 02:24
Who came up with the idea to truncate the output anyways? – j4hangir Dec 02 '20 at 20:09 — j4hangir, Dec 02 '20 at 20:09

Doorknob · Accepted Answer · 2015-09-12T03:34:57.020

165

From the journalctl manpage:

   The output is paged through less by default, and long lines are
   "truncated" to screen width. The hidden part can be viewed by using the
   left-arrow and right-arrow keys. Paging can be disabled; see the
   --no-pager option and the "Environment" section below.

If you don't want to constantly be using the left and right arrow keys, simply pipe it directly to less:

$ journalctl -xn | less

This will wrap lines that are too long for your terminal (the default behavior of less, which journalctl overrides).

Or, of course, if you don't mind possibly having to use your terminal's scrollback, you could use no pager at all:

$ journalctl -xn --no-pager

edited Sep 12 '15 at 03:34

answered Sep 12 '15 at 03:28

Doorknob

3,093

Ah, yes. I saw. – cuonglm Sep 12 '15 at 11:56
12

This is really frustrating. If pager is set to less, and LESS does not include -S, journalctl should not be applying -S to the invocation of less!! That is, setting PAGER=less and LESS=$x (where $x is any string that does not contain S) should give the desired behavior. – William Pursell Nov 11 '18 at 13:19
5

That is, journalctl should honor LESS, and the user should not have to also set SYSTEMD_LESS! (Apologies, doorknob, this is a bit of a rant that probably doesn't belong as a comment to your answer) – William Pursell Nov 11 '18 at 13:21
Silly William. Mr. Pottering knows what's best for you, and if you don't like it, you are obviously wrong. – dannysauer Oct 01 '19 at 17:21
3

For colored output: SYSTEMD_PAGER="less -r" journalctl -xn – V02460 Mar 28 '20 at 10:26
@V02460 what if I want to preserve journalctl colors after piping the output through grep? – Pablo A Jul 17 '21 at 20:11
2

@PabloA Prefixing SYSTEMD_COLORS=true helps. – V02460 Jul 18 '21 at 23:31
the right answer to keep colors and wrap text is SYSTEMD_LESS="FRXMK" journalctl - note excluded S – wick Dec 29 '23 at 12:41

score 31 · Answer 2 · answered Nov 09 '15 at 09:17

31

I also do:

journalctl -xn | less

But you can also set the SYSTEMD_LESS environment variable:

SYSTEMD_LESS=FRXMK journalctl -xn
# Or even
# SYSTEMD_LESS="" journalctl -xn
# The environment variable needs to be there, but can be the empty string

I got that from: [systemd-devel] [PATCH] pager: wrap long lines by default

Set it in your .bashrc and be done with it! :-)

That systemd needs to setup less specially and doesn't just honor the less defaults and the LESS environment seems a little arrogant to me, but hey, this works...

answered Nov 09 '15 at 09:17

Peter V. Mørch

633

SYSTEMD_LESS support is only recently added, e.g CentOS 7 does not have a version that supports it – jnas Nov 19 '15 at 09:02
Works at least on CentOS 7.5. – Vertigo Aug 14 '18 at 11:28
2

Great solution, I also added Defaults env_keep += "LESS SYSTEMD_LESS" to /etc/sudoers. It's for those times when I accidentally put sudo in front of e.g. systemctl status. – Metamorphic Sep 14 '18 at 17:51
2

It's not merely "a little arrogant", it's incredibly annoying. I hope it's not arrogance, but ignorance that drives this behavior. – William Pursell Nov 11 '18 at 13:22
Glanced at the source code. Specifically overriding the user's choice in LESS is just plain stupid. I'm still not sure if it's arrogance or ignorance, but probably a healthy combination of the two. – William Pursell Nov 12 '18 at 12:42
2

Hmmm. https://lists.freedesktop.org/archives/systemd-devel/2014-February/016814.html – William Pursell Nov 12 '18 at 12:58

score 7 · Answer 3 · answered Sep 12 '15 at 08:22

7

If the program already uses less (if not, pipe the output to it), you can enable/disable line wrapping by typing -S (in less), This works for other less options as well.

answered Sep 12 '15 at 08:22

Thomas Erker

2,857

score 5 · Answer 4 · answered Sep 09 '19 at 22:31

5

Note also that:

journalctl -f

will show you all the latest as it comes in and wrap like any normal human being (or even sysadmin) would expect to allow easy reading, copy-pasting, and everything else.

answered Sep 09 '19 at 22:31

mlncn

159

score 2 · Answer 5 · answered Jun 02 '21 at 10:20

2

$ SYSTEMD_PAGER="less +-S" journalctl

+ executes command on start and -S disable chopping.

You can also set this value for a session or save in rc/profile script.

answered Jun 02 '21 at 10:20

CheatEx

121

score 1 · Answer 6 · edited Jul 14 '20 at 18:51

1

This is the command I use for CentOS 7, which preserves coloring and wraps lines:

SYSTEMD_PAGER="less -r"  journalctl

edited Jul 14 '20 at 18:51

Liczyrzepa

654

answered Jul 14 '20 at 18:02

Dan M

119

score -1 · Answer 7 · edited Sep 08 '18 at 05:25

-1

I type in terminal,
journalctl | more, works great for me then I use arrows up or down.

edited Sep 08 '18 at 05:25

TPS

2,481

answered Sep 08 '18 at 02:01

user309707

11

journalctl: how to prevent text from truncating in terminal

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